An extremely limited haplotypic diversity within populations and a strikingly low divergence between European and Canadian haplotypes were found in pike Esox lucius. Certain haplotypes were associated with a particular geographical region in Europe: a widespread European and a restricted Hungarian-Norwegian type. The low haplotypic intraspecific divergence suggests a late Pleistocene expansion from an ancestral population. (C) 2003 The Fisheries Society of the British Isles.